The grieving widow of a National Guard officer allegedly murdered by one of his own men called the accused soldier yesterday a “traitor and a coward.”

In an emotional press conference outside her home in Milford, Barbara Allen, the wife of slain Lt. Louis Allen, said she learned that the Army had arrested Sgt. Alberto Martinez after the funeral in upstate Goshen on Thursday.

“I didn’t know what to think. I didn’t know what to feel. I didn’t know what to do,” she said.

Capt. Phillip Esposito of Pearl River in Rockland County was also slain in the attack.

“The man who did this to Lou, Phil and our families is a traitor and a coward,” Allen said.

“God may have mercy on him, but I hope no one else will.”

Allen’s father, Robert, told the Middletown Times Herald-Record newspaper: “I know that wherever he’s tried, I’ll be there because I want to see justice.”

Louis Allen, 34, a high school science teacher, and Esposito, a Wall Street broker, were killed June 7 by the explosion in Tikrit.

Martinez, of Troy, was arrested on Wednesday for the murders and is being held at a military facility in Kuwait.

All three were members of the 42nd Infantry Division.

In Pearl River yesterday, family members of Esposito remained behind closed doors.

“They’re holding up. But it’s horrible,” said family friend John Woods after visiting the family.

“It hurts. He was so young – only 30 years old. How could you ever think of something like that?”

In Pennsylvania, Barbara Allen clutched a book of photos and condolence notes as she spoke to reporters and was flanked by her sisters, Janice Clark and Mary Bell.

She gave a brief glimpse of the devastation the awful murders have caused for her and her four boys, ages 1 to 6.

“Not long ago, I had everything that is important in life. Today I am lost,” Allen, 32, said of life without her husband of 11 years. He enlisted in the military following the 9/11 attacks and recently volunteered to go to Iraq.

“Now I have to pick up the pieces for my boys.”

Asked what her plans are, Allen, a real-estate agent in nearby Orange County, N.Y., replied: “Day by day. I’m planning to live day by day.”

She said the military has offered her and her boys the services of a grief counselor.

The military is also offering grief counseling to Martinez’s family, said Col. Russell Catalano, rear detachment officer of the 42nd Infantry Division who visited Martinez’s wife and the home of his father yesterday.

He said the Martinez family is also “devastated” by what happened and that despite the charges, “he is still a member of the 42nd Infantry Division.”